Coupling device for mounting an airbag module to be oscillating on a vehicle steering wheel

ABSTRACT

A coupling device (16) for mounting an airbag module (14) to be oscillating on a steering wheel structure (12) of a vehicle steering wheel (10) includes a mounting member (18) which includes, relative to a steering wheel axis, an axial bottom side (20) which in the assembled state of the vehicle steering wheel (10) faces the steering wheel structure (12) as well as an opposite axial top side (22) which in the assembled state of the vehicle steering wheel (10) faces the airbag module (14), a contact face (24) for a damping element (26) provided on the axial bottom side (20) for oscillating coupling of the mounting member (18) to the steering wheel structure (12), and comprising a locking element (28) disposed on the top side (22) of the mounting member (18) for locking with the prefabricated airbag module (14), wherein the locking element (28) is configured so that the airbag module (14) can be coupled to the mounting member (18) by a locking connection substantially in an axially fixed manner or in an axially restrictedly movable manner.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 62/647,115, filed Mar. 23, 2018, the disclosure of which is herebyincorporated by reference in its entirety. This application is also acontinuation-in-part of International Application No. PCT/EP2017/070144,filed on Aug. 9, 2017, which claims priority from German Application No.DE 10 2016 124 530.5, filed on Dec. 15, 2016.

TECHNICAL FIELD

The invention relates to a coupling device for mounting an airbag moduleto be oscillating on a steering wheel structure of a vehicle steeringwheel as well as to a subassembly and to a vehicle steering wheelcomprising said coupling device.

BACKGROUND

In a plurality of vehicle steering wheels vibrations which the driverfeels uncomfortable with are occurring during idling or in particularspeed ranges of the vehicle. Said vibrations are due, inter alia, to therigid coupling of the steering wheel to the steering column.

It is known to employ so-called vibration dampers to avoid undesiredsteering wheel vibrations so as to adjust the natural frequency of theoverall system such that it is within an uncritical range. At present,for example the gas generator of an airbag module disposed within thesteering wheel is used as a counter-oscillating damper mass.

Since vibration damping improves with an increasing damper mass, in DE37 10 173 C2 already a vehicle steering is described in which the entireairbag module is advantageously used as a damper mass. By means of theshear stiffness of the vibration dampers used, the first naturalfrequency of the steering wheel/module system can be adjusted to be solow that it will be within a speed range of the vehicle in which highexciting amplitudes will not yet occur (for example at about 120 km/h).

In the case of oscillating airbag modules, the vibration dampers arecurrently also used to realize a horn function at the vehicle steeringwheel, with a horn contact being provided at the airbag module and arespective mating contact being provided at the steering wheelstructure. Such vehicle steering wheel is disclosed, for example, inU.S. Pat. No. 8,720,942 B2.

However, it has turned out that in steering wheels of this typeespecially on rough road tracks faulty activations of the vehicle hornwill occur or, as compared to steering wheels having no vibrationdamping, longer contacting distances or higher contacting forces arerequired to activate the vehicle horn. This entails clearances ofundesired large size at the vehicle steering wheel and impaired comfortwhen activating the vehicle horn.

SUMMARY

It is the object of the invention to provide a vehicle steering wheel ofsimple constructional design including a vibration damper having anintegrated horn function which has an as short actuating path aspossible and an as low actuating force as possible while a highfunctional safety is given.

In accordance with the invention, this object is achieved by a couplingdevice for mounting a prefabricated airbag module so as to beoscillating on a steering wheel structure of a vehicle steering wheel,comprising a mounting member including, relative to a steering wheelaxis, an axial bottom side which in the assembled state of the vehiclesteering wheel faces the steering wheel structure and an opposite axialtop side which in the assembled state of the vehicle steering wheelfaces an airbag module, a contact face provided on the axial bottom sidefor a damping element for oscillating coupling of the mounting member tothe steering wheel structure, as well as a locking element disposed onthe top side of the mounting member for engaging in the airbag module,wherein the locking element is configured so that the airbag module canbe coupled to the mounting member by a locking connection substantiallyin an axially fixed manner or in an axially restrictedly movable manner.Hence, with respect to the mounting member of the coupling device, onthe side of the steering wheel structure a vibration damping takes place(especially transversely to the steering wheel axis), whereas on themodule side a horn function can be realized (in the direction of thesteering wheel axis). In this way, the horn function and the vibrationdamping function are separated from each other in a simple manner sothat vibration excitations of the steering column and of the steeringwheel structure tightly connected thereto (e.g. on rough road tracks)are initially damped between the steering wheel structure and themounting member and no longer have an immediate effect on themodule-side horn function. An oscillating coupling of the mountingmember to the steering wheel structure by the damping element is to beunderstood within the scope of the present application in such way thatthe damping element enables damped vibration between the mounting memberand the steering wheel structure at least transversely to the steeringwheel axis, preferably also in the direction of the steering wheel axis.The maximum amplitude of possible vibration in the direction of thesteering wheel axis is preferably smaller than an axial actuating pathfor activating a vehicle horn.

The mounting member of the coupling device preferably is a mountingplate that extends substantially perpendicularly to the steering wheelaxis and especially includes plural locking elements, the lockingelements being preferably formed integrally with the mounting plate.Further, the locking elements may be identically spaced from thesteering wheel axis and may be arranged to be evenly spread in thecircumferential direction. This results in simple and quick assembly ofthe coupling device as well as in stable support of the airbag module.Alternatively, it is also imaginable, as a matter of course, to provideplural separate mounting members each having a locking element formounting the airbag module in an oscillating manner on the steeringwheel structure.

A damping element may be associated with each locking element, with thelocking elements and the associated damping elements being arrangedaxially in series.

According to one embodiment of the coupling device, on the axial topside of the mounting member a horn contact or an actuating member foractivating a beep upon contact between the horn contact and a matingcontact disposed at the airbag module is arranged, wherein the lockingelement is configured so that the airbag module can be coupled to themounting member in an axially restrictedly movable manner by the lockingconnection. In other words, in this case the entire airbag module isaxially displaced for actuating the vehicle horn, wherein both the horncontact and the mating contact are formed on components of the vehiclesteering wheel that are supported so as to be oscillating.

According to another embodiment, the coupling device includes a dampingelement which is adjacent to the axial bottom side of the mountingmember in the area of the contact surface and couples the mountingmember to the steering wheel structure in an oscillating manner so thatthe mounting member and the steering wheel structure are movablerelative to each other at least transversely to the steering wheel axis,especially wherein the damping element is preassembled at the axialbottom side of the mounting member. The damping element comprises avibration-damping material as well as, optionally, stop elements and/ormounting sleeves abutting on the vibration-damping material.

In this embodiment, the damping element preferably extends through anopening of the mounting member.

Moreover, the damping element may comprise an annular vibration-dampingmaterial having a radial shoulder, with an edge of the mounting memberopening forming a contact face and acting on the radial shoulder of thevibration-damping material.

In particular, the radial shoulder is in the form of a groove in thevibration-damping material, with the edge of the mounting member openingat least in portions engaging in the groove. This enables the dampingelement to be axially positioned and fixed on the mounting member in aquick and simple manner.

Incidentally, the object stated in the beginning is achieved by asubassembly comprising a steering wheel structure, an afore-describedcoupling device and a screw for mounting the coupling device to thesteering wheel structure which extends through the annularvibration-damping material, the vibration-damping material beingadjacent with an axial end face at least in portions to a screw head ofthe screw and/or being adjacent with an opposite axial end face at leastin portions to the steering wheel structure. The limitation of theaccommodating space for the vibration-damping material by componentspresent anyway such as the mounting member, the screw head and/or thesteering wheel structure is especially advantageous, because in suchcase separate mounting sleeves and/or stop elements can be dispensedwith. Ideally the damping element then is formed exclusively by thevibration-damping material.

Further, the invention comprises a subassembly including a steeringwheel structure, an afore-described coupling device and a dampingelement for oscillating coupling of the mounting member to the steeringwheel structure, wherein the damping element is arranged on the axialbottom side of the mounting member and is preassembled together with themounting member on the steering wheel structure.

The invention also comprises a subassembly having a prefabricated airbagmodule and an afore-described coupling device, wherein the airbagmodule, especially a module bottom of the airbag module, includes amating contact axially abutting on the horn contact, and wherein theairbag module is supported so as to be axially movable relative to themounting member for activating a beep.

The invention further relates to a subassembly comprising aprefabricated airbag module as well as an afore-described couplingdevice, wherein the airbag module includes a (manually operable) modulecover including a horn contact as well as another module componentincluding a mating contact axially abutting on the horn contact, themodule cover being supported to be axially movable relative to thefurther module component for activating a beep. In other words, the hornfunction is realized in this case “inside” the airbag module, whereinalso in this configuration variant the horn contact and the matingcontact are formed on components of the vehicle steering wheel supportedso as to be oscillating.

Finally, the object stated in the beginning is also achieved by avehicle steering wheel of an automotive vehicle comprising a steeringwheel structure, a prefabricated airbag module, an afore-describedcoupling device and a damping element for oscillating coupling of themounting member to the steering wheel structure, wherein the vehiclesteering wheel includes a horn contact and a mating contact axiallyabutting on the horn contact, and wherein both the horn contact and themating contact are formed on components of the vehicle steering wheelthat are supported to be oscillating. In particular, the coupling deviceand the damping element constitute a damper unit being preassembled onthe steering wheel structure. In this way, the vehicle steering wheelcan be assembled with especially little effort. The prefabricated damperunit is first connected, especially screwed, to the steering wheelstructure, whereupon the equally prefabricated airbag module is axiallyfed until it locks with the damper unit and thus is secured to thesteering wheel structure.

In an especially simply designed embodiment of the vehicle steeringwheel, the airbag module is secured to the steering wheel structureexclusively by the locking connection to the coupling device.

As an alternative, it is also imaginable, however, that an additional(locking) connection is provided between the airbag module and thesteering wheel structure which during normal driving of the vehicleadmits a limited relative movement, to be sure, but upon activation ofthe airbag module ensures that the airbag module does not completelydetach from the steering wheel structure. Consequently, the airbagmodule in this embodiment is secured to the steering wheel structure bymeans of the coupling device, wherein moreover another connectionindependent of the coupling device is provided between the airbag moduleand the steering wheel structure. This is of advantage as theconnections to the coupling device in this case need not be designed forthe extreme loads occurring, for example, upon activation of the airbagmodule.

According to one aspect, an apparatus for mounting an airbag module to asteering wheel structure of a vehicle steering wheel includes a couplingdevice for coupling the airbag module to the steering wheel structure.The coupling device includes a mounting member including a sleeve havinga central opening and being connected to the airbag module. Theapparatus also includes a fastening structure that extends through thecentral opening of the sleeve and connects the coupling device to thesteering wheel structure. The apparatus further includes a dampingelement constructed of a vibration damping material and being connectedto the sleeve. The damping element completely isolates the airbag modulefrom the steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, the damping element can have a cylindrical configuration and canbe supported in the central opening of the sleeve. The fasteningstructure can include a screw that extends through a central opening ofthe damping element.

According to another aspect, alone or in combination with any otheraspect, the damping element can include a surface feature that engages asurface feature of the mounting member to help maintain the connectionbetween the damping element and the mounting member.

According to another aspect, alone or in combination with any otheraspect, the damping element can include an upper end that engages a headof the screw and a lower end that engages the steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, the damping element can include a surface feature that engages asurface feature of the mounting member to help maintain the connectionbetween the damping element and the mounting member.

According to another aspect, alone or in combination with any otheraspect, the mounting member can be configured to receive a horn switchplate for sliding movement along an outer surface of the mountingmember. The apparatus can further include a spring that biases the hornswitch plate away from the steering wheel structure. The horn switchplate can be configured to slide along the outer surface of the mountingmember against a spring bias in response to displacement of the airbagmodule displacement resulting from pressure applied to an airbag modulecover.

According to another aspect, alone or in combination with any otheraspect, the horn switch plate can include an opening and a mounting ringfixed to the horn switch plate along a periphery of the opening. Themounting ring can encircle the outer surface of the mounting member andcan be constructed of a material that promotes the mounting ring slidingalong the outer surface of the mounting member.

According to another aspect, alone or in combination with any otheraspect, the mounting member can be configured to receive a horn ringthat encircles the outer surface of the mounting member. The spring canbias the horn ring and switch plate away from each other, and whereinthe mounting member comprises features that support the horn ring andswitch plate against movement away from each other due to the bias ofthe spring.

According to another aspect, alone or in combination with any otheraspect, the horn ring can support a first horn contact spaced axiallyfrom a second horn contact. The coupling device can be configured sothat axial movement of the switch plate toward the horn ring against thespring bias causes the first and second horn contacts to contact eachother.

According to another aspect, alone or in combination with any otheraspect, the screw can include a spacer portion that engages the steeringwheel structure when the screw is fully tightened. The damping elementcan have an axial length about equal to the axial length of the spacerportion so that the damping element engages a screw head at an upper endand engages the steering wheel structure at a lower end. The dampingelement can include a surface feature that engages a surface feature ofthe mounting member to support the mounting member on the steering wheelstructure so that the mounting member is free from contact with thesteering wheel structure and free from contact with the screw.

According to another aspect, alone or in combination with any otheraspect, the screw and the damping element can be the only components ofthe coupling device that contact the steering wheel structure.

According to another aspect, a subassembly can include a steering wheelstructure, an airbag module, and an apparatus according to any of theaspect set forth above.

According to another aspect, a coupling device for mounting an airbagmodule to be oscillating on a steering wheel structure of a vehiclesteering wheel includes a mounting member having an axial bottom siderelative to a steering wheel axis which in the assembled state of thevehicle steering wheel faces the steering wheel structure as well as anopposite axial top side which in the assembled state of the vehiclesteering wheel faces the airbag module. A contact face is provided onthe axial bottom side for a damping element for oscillating coupling ofthe mounting member to the steering wheel structure. A locking elementis disposed on the top side of the mounting member for locking with theairbag module. The locking element is configured so that the airbagmodule can be coupled to the mounting member by a locking connectionsubstantially in an axially fixed manner or in an axially restrictedlymovable manner.

According to another aspect, alone or in combination with any otheraspect, the mounting member can be a mounting plate which extendssubstantially perpendicularly to the steering wheel axis A andespecially includes plural locking elements.

According to another aspect, alone or in combination with any otheraspect, plural locking elements can be provided and a damping elementcan be associated with each locking element, wherein the lockingelements and the associated damping elements are arranged axially inseries.

According to another aspect, alone or in combination with any otheraspect, on the axial top side of the mounting member a horn contact oran actuating element for activating a beep can be arranged and thelocking element can be configured so that the airbag module can becoupled to the mounting member by the locking connection in an axiallyrestrictedly movable manner.

According to another aspect, alone or in combination with any otheraspect, the coupling device can include a damping element which contactsthe contact face on the axial bottom side of the mounting member andcouples the mounting member to the steering wheel structure in anoscillating manner so that the mounting member and the steering wheelstructure are movable relative to each other at least transversely tothe steering wheel axis A. The damping element can especially bepreassembled on the axial bottom side of the mounting member.

According to another aspect, alone or in combination with any otheraspect, the damping element can extend through an opening of themounting member.

According to another aspect, alone or in combination with any otheraspect, the damping element can include an annular vibration-dampingmaterial having a radial shoulder, wherein an edge of the opening formsa contact face and acts on the radial shoulder of the vibration-dampingmaterial.

According to another aspect, alone or in combination with any otheraspect, the radial shoulder can be configured as a groove in thevibration-damping material, wherein the edge of the mounting memberopening at least in portions engages in the groove.

According to another aspect, a subassembly can include a steering wheelstructure, a coupling device according to any of the preceding aspects,and a screw for mounting the coupling device on the steering wheelstructure which screw extends through the annular vibration-dampingmaterial. The vibration-damping material with an axial end face can beadjacent at least in portions to a screw head of the screw and/or withan opposite axial end face is adjacent at least in portions to thesteering wheel structure.

According to another aspect, a subassembly can include a steering wheelstructure, a coupling device according to any of the preceding aspects,and a damping element for oscillating coupling of the mounting member tothe steering wheel structure. The damping element can be arranged on theaxial bottom side of the mounting member and is preassembled togetherwith the mounting member on the steering wheel structure.

According to another aspect, a subassembly can include a prefabricatedairbag module and a coupling device according to any of the precedingaspects. The prefabricated airbag module can include a module coverincluding a horn contact as well as another module component including amating contact axially abutting on the horn contact, with the modulecover being supported to be axially movable relative to the furthermodule component for activating a beep.

According to another aspect, a subassembly can include a prefabricatedairbag module and a coupling device according to any of the precedingaspects. The prefabricated airbag module can include a mating contactaxially abutting on the horn contact, with the airbag module beingsupported to be axially movable relative to the mounting member foractivating a beep.

According to another aspect, a vehicle steering wheel of an automotivevehicle can include a steering wheel structure, a prefabricated airbagmodule, a coupling device according to any of the preceding aspects, anda damping element for oscillating coupling of the mounting member to thesteering wheel structure. The vehicle steering wheel can include a horncontact as well as a mating contact axially abutting on the horncontact. Both the horn contact and the mating contact can be formed oncomponents of the vehicle steering wheel that are supported so as to beoscillating.

According to another aspect, alone or in combination with any otheraspect, the airbag module can be secured to the steering wheel structureexclusively by the locking connection to the coupling device.

According to another aspect, alone or in combination with any otheraspect, the airbag module can be secured to the steering wheel structureby means of the coupling device. Moreover, another connectionindependent of the coupling device can be provided between the airbagmodule and the steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, a coupling device for mounting an airbag module on a steeringwheel structure of a vehicle steering wheel includes a mounting memberincluding a sleeve having a central opening and being connected to theairbag module. A damping element constructed of a vibration dampingmaterial is positioned in the sleeve and connected to the sleeve. Aspring encircles an outer surface of the mounting member. A fasteningstructure extends through the mounting member, damping element, andspring. The fastening structure connects the coupling device to thesteering wheel structure. The mounting member is configured to receive ahorn switch plate for sliding movement along the outer surface of themounting member. The spring exerts a spring bias against the horn switchplate and the mounting member in opposite directions, which biases thehorn switch plate away from the steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, the horn switch plate can be connected to and at least partiallysupports the airbag module. The horn switch plate can be configured toslide along the outer surface of the mounting member against the springbias in response to displacement of the airbag module resulting frompressure applied to an airbag module cover.

According to another aspect, alone or in combination with any otheraspect, the damping element completely isolates the airbag module fromthe steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, the horn switch plate can include an opening and a mounting ringfixed to the horn switch plate along a periphery of the opening. Themounting ring encircles the outer surface of the mounting member and isconstructed of a material that promotes the mounting ring sliding alongthe outer surface of the mounting member.

According to another aspect, alone or in combination with any otheraspect, the mounting member supports a first horn contact spaced axiallyfrom a second horn contact. The coupling device is configured so thataxial movement of the switch plate against the spring bias causes thefirst and second horn contacts to contact each other.

According to another aspect, alone or in combination with any otheraspect, the coupling device can include a plurality of mountingstructures each having an associated damping element, spring, andfastening structure, and the coupling device further includes at leastone bracket arm that interconnects the mounting structures.

According to another aspect, alone or in combination with any otheraspect, each mounting member includes a tab that supports a first horncontact spaced axially from a second horn contact. The coupling deviceis configured so that axial movement of the switch plate against thespring bias causes the first and second horn contacts to contact eachother.

According to another aspect, alone or in combination with any otheraspect, the coupling device includes four mounting structuresinterconnected by three bracket arms that extend between the mountingmembers in a U-shaped manner.

According to another aspect, alone or in combination with any otheraspect, the mounting member is configured to receive a horn ring thatencircles the outer surface of the mounting member. The spring biasesthe horn ring and switch plate away from each other. The mounting memberincludes features that support the horn ring and switch plate againstmovement away from each other due to the bias of the spring.

According to another aspect, alone or in combination with any otheraspect, the horn ring supports a first horn contact spaced axially froma second horn contact. The coupling device is configured so that axialmovement of the switch plate toward the horn ring against the springbias causes the first and second horn contacts to contact each other.

According to another aspect, alone or in combination with any otheraspect, the damping element has a cylindrical configuration and issupported in the central opening of the sleeve. The fastening structureincludes a screw that extends through a central opening of the dampingelement.

According to another aspect, alone or in combination with any otheraspect, the damping element includes a surface feature that engages asurface feature of the mounting member to help maintain the connectionbetween the damping element and the mounting member.

According to another aspect, alone or in combination with any otheraspect, the damping element includes an upper end that engages a head ofthe fastening structure and a lower end that engages the steering wheelstructure.

According to another aspect, alone or in combination with any otheraspect, the fastening structure includes a screw comprising a spacerportion that engages the steering wheel structure when the screw isfully tightened. The damping element has an axial length about equal tothe axial length of the spacer portion so that the damping elementengages a screw head at an upper end and engages the steering wheelstructure at a lower end. The damping element supports the mountingmember on the steering wheel structure so that the mounting member isfree from contact with the steering wheel structure and free fromcontact with the screw.

According to another aspect, alone or in combination with any otheraspect, the damping element supports the mounting member on the steeringwheel structure so that the mounting member is free from contact withthe steering wheel structure and free from contact with the fasteningstructure.

According to another aspect, alone or in combination with any otheraspect, the screw and the damping element are the only components of thecoupling device that contact the steering wheel structure.

According to another aspect, alone or in combination with any otheraspect, a subassembly includes a steering wheel structure, an airbagmodule, and a coupling device according to any of the preceding aspects.

DRAWINGS

Further features and advantages of the invention will be evident fromthe following description of preferred embodiments with reference to thedrawings, in which:

FIG. 1 shows a perspective exploded view of a vehicle steering wheelaccording to the invention comprising a coupling device according to theinvention in accordance with one embodiment;

FIG. 2 shows a schematic detailed section across the steering wheelaccording to FIG. 1 in the area of a locking element of the couplingdevice;

FIG. 3 shows a perspective exploded view of a vehicle steering wheelaccording to the invention comprising a coupling device according to theinvention in accordance with another embodiment;

FIG. 4 shows a schematic detailed section across the steering wheelaccording to FIG. 3 in the area of a locking element of the couplingdevice;

FIG. 5 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with one embodiment;

FIG. 6 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with another embodiment;

FIG. 7 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with yet another embodiment;

FIG. 8 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with yet another embodiment;

FIG. 9 shows a detailed section across the subassembly according to FIG.8 in the area of a mounting member of the coupling device according tothe invention;

FIG. 10 shows a perspective bottom view of the coupling device accordingto the invention in accordance with FIG. 9 in the area of the mountingmember;

FIG. 11 shows a perspective bottom view of a damping element for thecoupling device according to the invention in accordance with FIG. 10;

FIG. 12 shows a perspective view of a vehicle steering wheel comprisinga coupling device according to the invention; and

FIG. 13 shows a sectional view of a vehicle steering wheel according tothe invention comprising a subassembly in accordance with FIG. 8 and anassembled airbag module.

FIG. 14 is an exploded perspective view of a vehicle steering wheelincluding a coupling device for connecting an airbag module to thesteering wheel structure, according to another example configuration.

FIGS. 15 and 16 are sectional views of the steering wheel of FIG. 14,illustrating the components in different conditions.

FIG. 17 is a plan view illustrating an assembled condition of thesteering wheel of FIG. 14.

FIG. 18 is a sectional view illustrating an alternative configuration ofcertain components.

FIGS. 19 and 20 are perspective views illustrating another alternativeconfiguration of certain components.

FIG. 21 is a sectional view illustrating certain components of theconfiguration of FIGS. 19 and 20.

FIG. 22 is an exploded perspective view of a vehicle steering wheelincluding a coupling device for connecting an airbag module to thesteering wheel structure, according to another example configuration.

FIG. 23 are sectional views of the steering wheel of FIG. 22.

FIG. 24 is an exploded perspective view of a vehicle steering wheelincluding a coupling device for connecting an airbag module to thesteering wheel structure, according to another example configuration.

FIG. 25 are sectional views of the steering wheel of FIG. 24.

DESCRIPTION

The coupling device 16 comprises a mounting member 18 including,relative to a steering wheel axis A, an axial bottom side 20 which inthe assembled state of the vehicle steering wheel 10 faces the steeringwheel structure 12 as well as an opposite axial top side 22 which in theassembled state of the vehicle steering wheel 10 faces the airbag module14. On the axial bottom side 20 of the mounting member 18 a contact face24 for a damping element 26 for oscillating coupling of the mountingmember 18 to the steering wheel structure 12 is provided, whereas on theaxial top side 22 at least one locking element 28 is arranged forlocking with the airbag module 14.

The locking element 28 is configured so that the airbag module 14 can becoupled to the mounting member 18 by a locking connection substantiallyin an axially fixed manner or an axially restrictedly movable manner.

According to FIG. 1 the mounting member 18 is a mounting plate extendingperpendicularly to the steering wheel axis A and including three lockingelements 28. The mounting member 18 in this case is a metal part formedintegrally with the locking elements 28, wherein the locking elements 28are identically spaced apart from the steering wheel axis A and arearranged to be evenly spread in the circumferential direction.Alternatively, also configuration variants in which the mounting member18 is made from robust plastic material are imaginable, however.

The coupling device 16 in the shown embodiment includes three dampingelements 26 each of which is adjacent to a contact face 24 on the axialbottom side 20 of the mounting plate.

According to FIG. 1, a damping element 26 is associated with eachlocking element 28, wherein the locking elements 28 and the associateddamping elements 26 are arranged axially in series.

FIG. 2 illustrates a detailed section across the vehicle steering wheel10 according to FIG. 1 in the area of a damping element 26 and theassociated locking element 28 thereof.

The damping element 26 in this case comprises a vibration-dampingmaterial 27, for example an elastomer, as well as two stop elements 30and a mounting sleeve 32, each abutting on the vibration-dampingmaterial 27. The stop elements 30 are arranged axially on both sides ofthe vibration-damping material 27, while the mounting sleeve 32 extendsaxially between the stop elements 30.

The steering wheel structure 12 generally comprises a steering wheelarmature having a steering wheel rim, at least one spoke as well as ahub 34 and a hub plate 36. Moreover, the steering wheel structure 12usually further comprises a foam coating 38, for example made frompolyurethane, which at least partially surrounds the steering wheelarmature.

According to FIG. 2, the damping element 26 is secured to the steeringwheel armature via the mounting sleeve 32, with the mounting sleeve 32and the hub plate 36 forming a bayonet joint, for example.

It is further evident that the mounting member 18 including theintegrally formed locking element 28 is connected to the damping element26 by a screw 40 and to the steering wheel armature via the dampingelement 26 in this case.

The vibration-damping material 27 may be connected already in advance,e.g. by vulcanizing, to the mounting sleeve 32 and the stop elements 30so as to constitute the prefabricated damping element 26 with thelatter. Then the mounting sleeve 32 of each individual damping element26 is secured to the steering wheel structure 12, concretely to the hubplate 36 of the steering wheel structure 12, in the way of a bayonetlock. Finally, the mounting member 18 including its integrally formedlocking elements 28 is inserted and connected to the individual dampingelements 26 by the screws 40.

As will be exemplified later by way of FIG. 4, as a matter of coursealso alternatives for securing the coupling device 16 to the steeringwheel structure 12 are imaginable, however.

At any rate, in this way a subassembly comprising the steering wheelstructure 12, the afore-described coupling device 16 and at least onedamping element 26 for oscillating coupling of the mounting member 18 tothe steering wheel structure 12 is resulting, with the at least onedamping element 26 being arranged on the axial bottom side 20 of themounting member 18 and being preassembled together with the mountingmember 18 on the steering wheel structure 12.

According to FIGS. 1 and 2, the locking elements 28 of the couplingdevice 16 are rigid detent hooks which upon axially attaching theprefabricated airbag module 14 immerse in module bushes 42 and lock witha spring wire 43 mounted on the airbag module 14.

FIG. 3 illustrates a vehicle steering wheel 10 which differs from thesteering wheel design of FIG. 1 merely by a different configuration ofthe coupling device 16. In order to avoid repetitions, therefore theforegoing description is generally referred to and, in the following,mainly differences shall be discussed.

As compared to the embodiment according to FIG. 1, the coupling device16 according to FIG. 3 includes a different mounting on the steeringwheel structure 12 which is especially advantageous as regards theassembling effort. Instead of the stop elements 30 and the mountingsleeves 32, the coupling device 16 includes a base plate 44 forassembling the mounting member 18 on the steering wheel structure 12.

The vibration-damping material 27 in this case forms the damping element26 and can be connected, for example by vulcanizing, already in advanceto the mounting member 18 and the base plate 44 so that the dampingelement 26 is part of the prefabricated coupling device 16.

By way of the detailed section according to FIG. 4, it becomes evidentthat the base plate 44 of the coupling device 16 then only has to besecured to the steering wheel structure 12, wherein the base plate 44 inthe present embodiment is concretely screwed to the hub plate 36 of thesteering wheel structure 12 by a screw 46.

For further reducing the assembling effort for the coupling device 16,alternatively or additionally to screwing it is also imaginable to foamthe base plate 44 at least on the edge side into the foam coating 38 andthus to secure it to the steering wheel structure 12.

In order to prevent the airbag module 14 when being activated fromcompletely detaching from the steering wheel structure 12, directly onthe steering wheel structure 12 catch elements may be provided whichduring normal driving are spaced apart from the airbag module 14 andonly when the module is activated act immediately on the airbag module14 and withhold the module 14. Said catch elements are, for example,catch hooks or stop hooks 80 integrally formed on the steering wheelarmature of the steering wheel structure 12 (cf. FIG. 12).

According to a specific variant of the vehicle steering wheel 10 suchcatch elements are not provided. The airbag module 14 in that case issecured to the steering wheel structure 12 exclusively via the couplingdevice 16. In order to fix the locking element 28 of the coupling device16 especially tightly and reliably on the steering wheel structure 12 inthis case, a screw 48 indicated in broken lines in FIG. 4 is providedalternatively or additionally to the screw 46.

As regards a horn function of the steering wheel 10, it is especiallyadvantageous when the vehicle steering wheel 10 includes a horn contact50 as well as a mating contact 52 axially abutting on the horn contact50, wherein both the horn contact 50 and the mating contact 52 areformed at components of the vehicle steering wheel 10 that are supportedto be oscillating.

Components supported to be oscillating in this context are, for example,the mounting member 18 of the coupling device 16 as well as the airbagmodule 14 including all of its module components.

In FIGS. 5 to 7 various options for realizing such horn function on thevehicle steering wheel 10 are exemplified.

FIG. 5 illustrates a subassembly for the vehicle steering wheel 10comprising a prefabricated airbag module 14 and a coupling device 16which has a horn contact 50 for activating a beep on the top side 22 ofthe mounting member 18.

The airbag module 14 includes a mating contact 52 axially abutting onthe horn contact 50, wherein the (entire) airbag module 14 is supportedto be axially movable relative to the mounting member 18 for activatingthe beep. In other words, the prefabricated airbag module 14 hence iscoupled to the mounting member 18 to be axially restrictedly movable inthe assembled state of the vehicle steering wheel 10 via the lockingconnection to the locking elements 28 of the coupling device 16.

FIG. 6 illustrates another subassembly for the vehicle steering wheel 10which differs from the embodiment according to FIG. 5 merely by the factthat the airbag module 14 includes both the horn contact 50 and themating contact 52 axially spaced apart from the horn contact 50. Themounting member 18 supported to be oscillating includes at least oneaxially projecting actuating element 53 being axially abutting on thehorn contact 50, wherein two hook-shaped projections are provided asactuating elements 53 in the shown variant. For activating the horn, the(entire) airbag module 14 then is moved axially in the direction of themounting member 18 against a spring force, with the horn contact 50being deformed or displaced in the direction of the mating contact 52 bythe at least one actuating element 53 until the desired beep sounds whenthe contacts will touch each other.

Finally, FIG. 7 shows another embodiment of the subassembly for thevehicle steering wheel 10 comprising a prefabricated airbag module 14and a coupling device 16, with the horn function being integrated in theairbag module 14. The prefabricated airbag module 14 in this caseincludes a module cover 54 having the horn contact 50 and another modulecomponent 56 having the mating contact 52 axially abutting on the horncontact 50, wherein the module cover 54 is supported to be axiallymovable relative to the further module component 56 for activating thebeep.

As compared to the configuration variants according to FIGS. 5 and 6,hence a horn activation according to FIG. 7 is not effectuated bydisplacing the entire airbag module 14 but by a relative movementbetween the module cover 54 and the further module component 56, forexample a module casing.

However, all configuration variants share the fact that all componentsrequired for horn activation such as horn contacts 50, mating contacts52 and/or actuating elements 53 are supported to be oscillating on thesteering wheel structure 12. In other words, in a vehicle steering wheel10 including a vibration damper all of the components required foractivating the horn are part of the damper mass of the steering wheelvibration damper.

This is also applicable to the further embodiment of the coupling device16 shown in FIGS. 8 to 13 in which the damping element 26 extendsthrough an opening 58 of the mounting member 18.

In the present embodiment, the damping element 26 is made from thevibration-damping material 27 that is annular and has a radial shoulderon the outside. The mounting member opening 58 has an opening edgeincluding radially inwardly protruding projections 60, 62 which form thecontact face 24 for the damping element 26 and act on the radialshoulder of the vibration-damping material 27.

The radial shoulder in the vibration-damping material 27 is a peripheralgroove 64 according to FIG. 11, with the opening edge, concretely theprojections 60 of the opening edge engaging in the groove 64. In thisway, the elastic ring made from vibration-damping material 27 can bequickly and easily attached to the opening 58 so that the dampingelement 26 is axially positioned and fixed on the mounting member 18with minimum effort. Each projection 60 of the mounting member 18includes an axial bottom side 20 facing the steering wheel structure 12and forms a contact face 24 for the damping element 26 which in thepresent case corresponds to the annular vibration-damping material 27.

FIGS. 8 and 9 illustrate a subassembly comprising a steering wheelstructure 12, a coupling device 16 and a screw 66 for assembling thecoupling device 16 on the steering wheel structure 12, with the screw 66extending through the annular vibration-damping material 27.

With respect to a screw axis S the screw 66 extends from a screw head 68in the axial direction via a screw shank 70 to a free shank end 72. Thescrew shank 70 is stepped having a spacer portion 74 abutting on thescrew head 68 and a thread portion 76 abutting on the spacer portion 74toward the free shank end 72, which thread portion is separated from thespacer portion 74 by a step 78. The thread portion 76 has a smallershank diameter than the spacer portion 74 and is screwed into the hubplate 36 of the steering wheel structure 12 until the step 78 contactsthe hub plate 36 and prevents further screwing.

The locking element 28 extends in the axial direction from the mountingmember 18 to a free end and is substantially hollow-cylindrical, with alocking projection being integrally formed at the free end. An outerdiameter of the screw head 68 is somewhat smaller than an inner diameterof the locking element 28 so that the screw 66 can be inserted into thelocking element 28 and extends through the opening 58 of the mountingmember 18 into the hub plate 36. Said screwing of the mounting member 18in the area of the locking element 28 contributes to an especiallycompact design of the coupling device 16.

According to FIG. 9, an axial dimension of the spacer portion 74 of thescrew 66 is somewhat larger than an axial dimension of the mountingmember 18 in the area of the damping element 26 so that a predeterminedmovement of the mounting member 18 relative to the steering wheelstructure 12 is possible for vibration damping.

An axial dimension of the damping element 26 is at least as large as theaxial dimension of the spacer portion 74 so that the vibration-dampingmaterial 27 is axially positioned as well as preferably slightlycompressed when the screw 66 is tightened.

The groove 64 in the vibration-damping material 27 is disposed so thatin a non-excited idle position of the vehicle steering wheel 10, themounting member 18 is held to be axially spaced apart from the screwhead 68 and the hub plate 36, especially substantially axially centrallybetween the screw head 68 and the hub plate 36, via its projections 60engaging in the groove 64.

Just as the projections 60, also the projections 62 of the mountingmember 18 axially abutting on the screw head 68 have axial bottom sides20 facing the steering wheel structure 12 each of which forms a contactface 24 for the damping element 26. Primarily the projections 62 serveas stops of the mounting member 18 on the screw head 68, however, so asto define a maximum relative movement between the mounting member 18 andthe steering wheel structure 12.

The vibration-damping material 27 is adjacent with an axial end face atleast in portions to the screw head 68 of the screw 66 and is adjacentwith an opposite axial end face at least in portions to the steeringwheel structure 12.

Thus, an accommodating space for the vibration-damping material 27 isdefined in the axial direction by the screw head 68 and the steeringwheel structure 12 as well as in the radial direction by the spacerportion 74 of the screw shank 70 and the mounting member 18. Therefore,separate stop elements 30 and mounting sleeves 32 (as shown in FIG. 2,for example) can advantageously be dispensed with.

If exceptionally high forces, as they occur e.g. upon activation of theairbag module 14, cannot be transmitted by the connection between theairbag module 14 and the coupling device 16 and/or by the connectionbetween the coupling device 16 and the steering wheel structure 12, itis imaginable that the airbag module 14 is not only secured to thesteering wheel structure 12 by means of the coupling device 16 but thatmoreover a further connection between the airbag module 14 and thesteering wheel structure 12 independent of the coupling device 16 isprovided.

This is illustrated, for example, in a vehicle steering wheel 10according to FIG. 12. In the shown steering wheel design, a couplingdevice 16 and a steering wheel structure 12 are provided, wherein amounting member 18 of the coupling device 16 in the form of a mountingplate is connected to the steering wheel structure 12 in an oscillatingmanner and includes locking elements 28 for locking with the airbagmodule 14. Furthermore, at the steering wheel structure 12 there areprovided catch elements which during normal driving are spaced apartfrom the airbag module 14 and only upon activation of the module actimmediately on the airbag module 14 and withhold the same. According toFIG. 12, said catch elements are detent hooks 80 integrally formed onthe steering wheel armature of the steering wheel structure 12.

FIG. 13 illustrates the vehicle steering wheel 10 according to FIG. 12with a coupling device 16 according to FIG. 9 and an assembled airbagmodule 14. Herefrom it is evident that the spring wire 43 tightlyconnected to the airbag module 14 engages both in the locking elements28 of the coupling device 16 and in the detent hooks 80 of the steeringwheel structure 12.

A further embodiment of the coupling device 16 shown in FIGS. 14-17. Inthis embodiment, as with other embodiments, the coupling device 16includes a vibration damping element 26 that extends through an opening58 of the mounting member 18.

FIG. 14 is an exploded view illustrating how the coupling device 16interfaces with the steering wheel structure 12 and the airbag module14. More specifically, the coupling device 16 connects a horn switchplate 100 to the hub plate 36 of the steering wheel structure 12. Tofacilitate this connection, the hub plate 36 includes cylindricalmounting projections 110 each of which includes a threaded centralopening 112. The switch plate 100 can be a portion of the airbag module14 or can be a separate component connectable with the airbag module.

The switch plate 100 can be constructed of metal and over-molded with aplastic or elastomeric material. The switch plate 100 includes horncontacts 102, such as rivets, that form part of a horn actuationcircuit. The switch plate 100 also includes mounting openings 104 inwhich mounting rings 106 are fixed. In the configuration illustrated inFIG. 14, there are four horn contacts 102, each of which is positionedadjacent to a corresponding mounting opening 104/mounting ring 106combination. The mounting rings 106 and their respective mountingopenings 104 are arranged and spaced on the switch plate 100 tocorrespond to the arrangement and spacing of the mounting projections110 and their respective openings 112 on the hub plate 36.

As with other embodiments disclosed herein, the coupling device 16includes a mounting member 18, a damping element 26, and a shoulderscrew 66. Additionally, the coupling device 16 includes a horn ring 120and a spring 140.

Referring to FIGS. 15-16, the damping element 26 is made fromvibration-damping material 27 and has a generally cylindricalconfiguration including a central cylindrical inner surface 150 defininga central opening 148. The damping element 26 also includes acylindrical outer surface 152 and a surface feature in the form of anannular groove 154 that extends into the outer surface and has agenerally rectangular profile. The damping element 26 further includesupper and lower (as viewed in the figures) axial end surfaces 156, 158,respectively.

The vibration-damping material 27 is a deformable and resilientmaterial, such as an elastomer (i.e., a natural or synthetic polymerhaving elastic properties, e.g., rubber).

The mounting member 18 has a generally cylindrical configuration in theform of a sleeve that includes a central cylindrical inner surface 160that defines the central opening 58 that extends through the mountingmember. The mounting member 18 also includes a cylindrical outer surface162 and a surface feature in the form of an annular projection 164 thatextends outward from the inner surface into the central opening 58 andhas a generally rectangular profile. The mounting member 18 alsoincludes upper and lower axial end surfaces 166, 168, respectively. Themounting member 18 further includes an upper flange 170 and a lowerlocking element 172 that project radially outward from the upper andlower ends, respectively, of the mounting member.

The damping element 26 is positioned in the central opening 58 of themounting member 18 such that their respective surface features engageeach other, i.e., the annular projection 164 on the mounting member isreceived in the annular groove 154 of the damping element, which securesthe damping element in the mounting member. In this assembled condition,the damping element 26 and the mounting member 18 are aligned such thatthe upper end 156 of the damping element extends slightly verticallyabove the upper end 166 of the mounting member. The lower end 168 of thedamping element 26 is positioned within the central opening 58 of themounting member 18, above the lower end 168.

The horn ring 120 has a circular bottom wall 180 with a central circularopening 182 and a cylindrical side wall 184 that extends upward (asviewed in the figures) from an annular periphery of the bottom wall. Acontact arm 186 extends laterally from the side wall 184 and includes ahorn contact 103, such as a rivet, that projects upward.

The lower end 168 of the mounting member 18 extends through the opening182 of the horn ring 120. The lower locking elements 172 includeretention surfaces 176 that engage a lower surface 188 of the bottomwall 180 of the horn ring 120. An inner surface 190 of the bottom wall180 defining the central opening 182 encircles the outer surface 162 ofthe mounting member 18. As shown in FIG. 15, there can be some spacebetween the inner surface 190 and the outer surface 162.

The mounting ring 106 has a generally ring-shaped configuration andincludes an upper rim 200 and a lower rim 202 separated by an annulargroove 204. A central opening 206 extends through the mounting ring 106.An annular edge 208 of the switch plate 100 defining the mountingopening 104 is received in the annular groove 204 to connect themounting ring 106 to the switch plate.

The upper end 166 of the mounting member 18 extends through the opening206 of the mounting ring 106. The upper flange 170 includes a lowersurface 210 that engages an upper surface 212 of the mounting ring 106.An inner surface 214 of the mounting ring 106 defining the centralopening 206 encircles the outer surface 162 of the mounting member 18.As shown in FIG. 15, there can be some space between the inner surface214 and the outer surface 162.

The spring 140 is positioned around or encircling the outer surface 162of the mounting member 18. The spring extends along the outer surface162 between the mounting ring 106 and the horn ring 120. The spring 140has an upper end 216 that engages a bottom surface 218 of the mountingring 106 and a lower end 220 that engages an upper surface 222 of thehorn ring 120. The lower end 216 of the spring 140 can be seated in anannular space defined by the mounting member 18, the bottom wall 180 ofthe horn ring 120, and the side wall 184 of the horn ring.

The shoulder screw 66 includes a screw head 68 and a shank 70. The shank70 includes a spacer portion 74 and a threaded portion 76. The spacerportion 74 has a diameter that is greater than the threaded portion 76.An annular stop portion 78 of the shank 70 extends between thesediameters.

In the assembled condition of the portion of the steering wheel 10illustrated in FIGS. 15-16, the mounting projection 110 of the hub plate36 is received in the mounting structure 18. The shoulder screw 66 isinstalled with outer threads of the threaded portion 76 of the shank 70engaging the threaded central opening 112 of the mounting projection110. This aligns the components of the coupling device 16 with themounting projection 110 and the mounting opening/ring 104, 106 along ascrew axis S.

Tightening the screw 66 causes the stop portion 78 to engage an endsurface 230 of the mounting projection 110. The axial length of thedamping element 26 coincides with the length of the screw shank spacerportion 70, so that the upper end 156 of the damping element engages thescrew head 68 and the lower end 158 of the damping element engages theend surface 230 of the mounting projection 110. The mounting member 18,having an axial length greater than the damping element 26, extendsdownward beyond the upper end surface 230 of the mounting projection110, terminating with the lower end 168 spaced from the hub plate 36.

The inside diameter of the mounting member 18 is greater than theoutside diameter of the mounting projection 110, thereby creating anannular clearance 232 between the mounting member and the mountingprojection. The damping element 26 extends axially above the flange 170of the mounting element such that the screw head 68 engages the dampingelement, but not the flange. This creates an annular clearance 238between the flange 170 and the screw head 68.

From the above, it will be appreciated that the configuration of thecoupling device 16, the switch plate 100, and the hub plate 36 is suchthat the mechanical interface between the steering wheel/hub plate andthe airbag module is only through the vibration-damping material 27 ofthe damping element 26. The clearances 232 and 238 space the airbagmodule 14 from the rigid structure of the steering wheel structure 12and the screw 66, which is mechanically fastened to the steering wheelstructure. The damping element 26 de-couples the airbag module 14 fromthe steering wheel structure 12 and can therefore act as a vibrationdamper to avoid undesired steering wheel vibrations. The damping element26 suspends the mounting member 18, and the airbag module 14 connectedto the mounting member, from the steering wheel structure 12 andtherefore completely isolates the airbag module from the steering wheelstructure. The airbag module 14 can therefore oscillate relative to thesteering wheel structure 12.

The switch plate 100 is configured for movement along the axis Srelative to the horn ring 120 against the bias of the spring 140. Thematerials used to construct the mounting member 18 and the mounting ring106 are selected so that the mounting ring 106 can slide easily over theouter surface 162 of the mounting member. This sliding movement can alsobe facilitated by the clearance between the inner surface 214 of themounting ring 106 and the outer surface 162 of the mounting structure.The mounting member 18 and mounting ring 106 can, for example, beconstructed of a plastic or elastomeric material.

The switch plate 100 can be moved along the axis S against the bias ofthe spring 140 when the operator presses or pushes on the airbag module14, such as on the airbag module cover 54. This moves the switch plate100 against the bias of the spring 140 from the position illustrated inFIG. 15 to the position illustrated in FIG. 16, in which the horncontacts 102 and 103 engage each other.

While the configuration and function of the components of the steeringwheel 10 have been described in terms of a single coupling device 16 andmounting location on the hub plate 36 and switch plate 100, it should beappreciated that the configurations and functions are identical at all(four) mounting locations on the steering wheel. This is shown in FIG.17, which shows the hub plate 36, the horn plate 100 (in phantom lines),and the coupling devices 16 connecting the horn plate to the hub plateat four locations.

From the above, it will be appreciated that the configuration of thesteering wheel 10 de-couples the vibration damping function of thecoupling device 16 from the horn switch actuation function of thecoupling device. Actuation of the horn does not depend on airbag module14 movement relative to the hub plate 36 facilitated by the dampingelement 26. Conversely, vibration damping does not depend on airbagmodule 14 movement relative to the hub plate 36 facilitated by the hornactuation components.

FIG. 18 illustrates another configuration of the steering wheel 10. Thesteering wheel configuration of FIG. 18 is similar or identical in someaspects to the configuration of FIGS. 14-17 with a few exceptions. Inthe configuration of FIG. 18, the horn ring 120 is omitted from thecoupling device 16 and the hub plate 36 is reconfigured to carry thehorn contact 103. In this configuration, the lower end 220 of the spring140 can abut an upper surface of the hub plate, which can allow for theelimination of the lower locking element of the mounting member 18.Functionally, the configuration of FIG. 18 is identical to theconfiguration of FIGS. 14-17, and can therefore provide the vibrationdamping and horn switch actuation functionality described above.

FIGS. 19-21 illustrate another configuration of the coupling device 16.In the configuration of FIGS. 19-21, a single component performs thefunctions of the both the mounting member and the horn ring for all fourmounting locations. As shown in FIG. 19, a mounting structure 240includes four mounts 242, each of which include a base 244 for receivingthe lower end of the spring 140. Centered within and extending upwardfrom the base 244 is a sleeve 246. The base 244 has the general form andperforms the functions of the horn ring in FIGS. 14-17. The sleeve 246has the general form and performs the functions of the mounting memberin FIGS. 14-17. At each mount 242 also includes a tab 248 for supportingthe horn contact 103.

The mounts 242 are interconnected with each other by bracket arms 250that extend in a U-shaped manner between the mounts. The singlecomponent construction of the mounting structure 240 advantageously canreduce the complexity of the assembly and the number of components usedto assemble the steering wheel, while simultaneously providing thevibration damping and horn switch actuation functionality describedabove.

As shown in FIG. 19, the mounts 242 are configured to receive thedamping element 26 and the horn switch plate 100, including the mountingrings 106, in the same manner described above in regard to theconfiguration of FIGS. 14-17. This allows the shoulder screws 66 (seeFIG. 20) to secure the horn switch plate 100 and the mounting structure240 to the steering wheel hub plate (not shown), again in the samemanner described above in regard to the configuration of FIGS. 14-17.

A further embodiment of the coupling device 16 shown in FIGS. 22-23. Inthis embodiment, as with other embodiments, the coupling device 16includes a vibration damping element 26 that extends through an opening58 of a mounting member 18. FIGS. 22-23 illustrate the coupling device16 implemented in a steering wheel 12 to connect an airbag module 14 toa steering wheel structure 12. The steering wheel configuration of FIGS.22-23 is similar or identical in some aspects to previousconfigurations, such as the configuration of FIGS. 14-17, with a fewexceptions. In the configuration of FIGS. 22-23, the screw is omittedand the damping element 26 is configured to both connect the airbagmodule 14 to the steering wheel structure 12 and provide steering wheelvibration damping.

FIG. 22 is an exploded view illustrating how the coupling device 16interfaces with the steering wheel structure 12 and the airbag module14. More specifically, the coupling device 16 connects a horn switchplate 100 to the hub plate 36 of the steering wheel structure 12. Tofacilitate this connection, the hub plate 36 includes mounting locations110 each of which includes a central opening 112. The switch plate 100can be a portion of the airbag module 14 or can be a separate componentconnectable with the airbag module.

In terms of horn switch functionality, the configuration of FIGS. 22-23is essentially similar or identical to that of the configuration ofFIGS. 14-17. The switch plate 100 moves toward the horn ring 120 againstthe bias of the spring 140 in response to occupant pressure applied tothe airbag module 14 to bring together the horn contacts 102, 103. Therelative movement of the switch plate 100 to the horn ring 120 isindependent of compression/deflection of the damping element 26.

Referring to FIG. 23, the damping element 26 is made fromvibration-damping material 27 and has a generally cylindricalconfiguration of varying diameters along its length. The damping element26 includes an upper head portion 300 for connecting to the mountingmember 18, a central body portion 310 positioned within the mountingmember 18, and a lower fastening portion 320 connectable with thesteering wheel structure 12.

The head portion 300 has an outer diameter about equal to the innerdiameter of the mounting member 18. The diameter of the head portion 300can be slightly larger than the inner diameter of the mounting member 18so as to form an interference fit with the mounting member. An annulargroove 302 receives an inwardly projecting annular locking rim 304 ofthe mounting member, which locks the damping member 26 in the mountingmember 18.

The body portion 310 extends from the head portion 300 inside themounting member 18 and has an outer diameter that creates an annularclearance between the body portion and the mounting member. At a lowerextent, the body portion 310 includes an annular guide rim 312 thatextends outward into engagement with an inner surface of the mountingmember 18. The guide rim 312 helps maintain the alignment of themounting member 18 and damping member 26 along the axis S.

The fastening portion 320 includes an upper annular flange 322 and alower locking head 324 spaced apart by an annular locking groove 326.The fastening portion 320 extends through the central opening 112 of themounting location 110 so that an annular rim portion 328 of the hubplate 36 defining the central opening is received in the locking groove326. This connects the airbag module 14 to the steering wheel structure12.

The coupling device 16 is configured so that the mechanical interfacebetween the steering wheel structure 12/hub plate 36 and the airbagmodule 14 is only through the vibration-damping material 27 of thedamping element 26. The head portion 300 of the damping element 26 isconnected to the mounting structure 18, and the fastening portion 320 isconnected to the hub plate 36. The upper annular flange 322 of thefastening portion is positioned between the lower end of the mountingstructure 18 and the hub plate 36. The damping element 26 thusde-couples the airbag module 14 from the steering wheel structure 12 andcan therefore act as a vibration damper to avoid undesired steeringwheel vibrations.

From the above, it will be appreciated that the configuration of thesteering wheel 10 de-couples the vibration damping function of thecoupling device 16 from the horn switch actuation function of thecoupling device. Actuation of the horn does not depend on airbag module14 movement relative to the hub plate 36 facilitated by the dampingelement 26. Conversely, vibration damping does not depend on airbagmodule 14 movement relative to the hub plate 36 facilitated by the hornactuation components.

A further embodiment of the coupling device 16 shown in FIGS. 24-25. Inthis embodiment, as with other embodiments, the coupling device 16includes a vibration damping element 26 and a mounting member 18. FIGS.24-25 illustrate the coupling device 16 implemented in a steering wheel12 to connect an airbag module 14 to a steering wheel structure 12. Thesteering wheel configuration of FIGS. 24-25 is similar or identical insome aspects to previous configurations. In the configuration of FIGS.24-25, the damping element 26 is positioned outside the mounting member18 and interfaces directly with the hub plate 36 to connect the airbagmodule 14 to the steering wheel structure 12. To facilitate thisconfiguration, the coupling device 16 includes a fastener including aninternally threaded bolt 350 and an externally threaded stud 352 formaking the connection between the steering wheel structure 12 and theairbag module 14.

FIG. 24 is an exploded view illustrating how the coupling device 16interfaces with the steering wheel structure 12 and the airbag module14. More specifically, the coupling device 16 connects a horn switchplate 100 to the hub plate 36 of the steering wheel structure 12. Tofacilitate this connection, the hub plate 36 includes mounting locations110 each of which includes a central opening 112. The switch plate 100can be a portion of the airbag module 14 or can be a separate componentconnectable with the airbag module.

In terms of horn switch functionality, the configuration of FIGS. 24-25is essentially similar or identical to that of other configurationsdisclosed herein. The switch plate 100 moves toward the horn ring 120against the bias of the spring 140 in response to occupant pressureapplied to the airbag module 14 to bring together the horn contacts 102,103. The relative movement of the switch plate 100 to the horn ring 120is independent of compression/deflection of the damping element 26.

Referring to FIG. 25, the damping element 26 is made fromvibration-damping material 27 and has a generally cylindricalconfiguration of varying diameters along its length. The damping element26 has a ring shaped configuration including an open central passage 360and includes an upper rim 362, a lower rim portion 364, and a centralannular groove 366 positioned between the rims.

The damping element 26 is positioned over the mounting member 18 so thata sleeve portion 368 of the mounting member passes through the centralpassage 360. The mounting member 18 includes a lower rim portion 370against which the lower rim portion 364 of the damping element 26 rests.The horn switch ring 120 is positioned over the sleeve portion 368 ofthe mounting member 18 and rests against the upper rim portion 362 ofthe damping element 26. An upper locking member 372 of the mountingmember retains the horn switch ring 120 on the mounting member 18.

The stud 352 passes through the switch plate 100 and extends into acentral passage 374 of the mounting member 18. A head 354 of the stud352 engages the switch plate 100. The bolt 350 passes through thecentral passage 374 of the mounting member 18 and engages and isthreaded onto the stud 352, which maintains the components aligned alongthe axis S. A head 356 of the bolt 350 engages the lower rim portion 370of the mounting member 18 on a side opposite the damping element 26. Theswitch plate 100 rides along the stud 352 against the bias of the springin response to pressure applied to the airbag module 14 to move the horncontacts 102, 103 into engagement with each other.

The coupling device 16 is configured so that the mechanical interfacebetween the steering wheel structure 12/hub plate 36 and the airbagmodule 14 is only through the vibration-damping material 27 of thedamping element 26. The damping element 26 is the only structure thatengages the hub plate 36 to couple the airbag module 14 to the steeringwheel structure 12. The damping element 26 thus de-couples the airbagmodule 14 from the steering wheel structure 12 and can therefore act asa vibration damper to avoid undesired steering wheel vibrations.

From the above, it will be appreciated that the configuration of thesteering wheel 10 de-couples the vibration damping function of thecoupling device 16 from the horn switch actuation function of thecoupling device. Actuation of the horn does not depend on airbag module14 movement relative to the hub plate 36 facilitated by the dampingelement 26. Conversely, vibration damping does not depend on airbagmodule 14 movement relative to the hub plate 36 facilitated by the hornactuation components.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes and modifications within the skill of the art areintended to be covered by the appended claims.

1. A coupling device for mounting an airbag module to be oscillating ona steering wheel structure of a vehicle steering wheel, comprising: amounting member having an axial bottom side relative to a steering wheelaxis which in the assembled state of the vehicle steering wheel facesthe steering wheel structure as well as an opposite axial top side whichin the assembled state of the vehicle steering wheel faces the airbagmodule; a contact face provided on the axial bottom side for a dampingelement for oscillating coupling of the mounting member to the steeringwheel structure; and a locking element disposed on the top side of themounting member for locking with the airbag module, wherein the lockingelement is configured so that the airbag module can be coupled to themounting member by a locking connection substantially in an axiallyfixed manner or in an axially restrictedly movable manner.
 2. Thecoupling device according to claim 1, wherein the mounting member is amounting plate which extends substantially perpendicularly to thesteering wheel axis and especially includes plural locking elements. 3.The coupling device according to claim 1, wherein plural lockingelements are provided and a damping element is associated with eachlocking element, wherein the locking elements and the associated dampingelements are arranged axially in series.
 4. The coupling deviceaccording to claim 1, wherein on the axial top side of the mountingmember a horn contact or an actuating element for activating a beep isarranged and the locking element is configured so that the airbag modulecan be coupled to the mounting member by the locking connection in anaxially restrictedly movable manner.
 5. The coupling device according toclaim 1, wherein the coupling device includes a damping element whichcontacts the contact face on the axial bottom side of the mountingmember and couples the mounting member to the steering wheel structurein an oscillating manner so that the mounting member and the steeringwheel structure are movable relative to each other at least transverselyto the steering wheel axis, especially wherein the damping element ispreassembled on the axial bottom side of the mounting member.
 6. Thecoupling device according to claim 5, wherein the damping elementextends through an opening of the mounting member.
 7. The couplingdevice according to claim 6, wherein the damping element comprises anannular vibration-damping material having a radial shoulder, wherein anedge of the opening forms a contact face and acts on the radial shoulderof the vibration-damping material.
 8. The coupling device according toclaim 7, wherein the radial shoulder is configured as a groove in thevibration-damping material, wherein the edge of the mounting memberopening at least in portions engages in the groove.
 9. A subassemblycomprising: a steering wheel structure; a coupling device according toclaim 7; and a screw for mounting the coupling device on the steeringwheel structure which screw extends through the annularvibration-damping material, wherein the vibration-damping material withan axial end face is adjacent at least in portions to a screw head ofthe screw and/or with an opposite axial end face is adjacent at least inportions to the steering wheel structure.
 10. A subassembly comprising:a steering wheel structure; a coupling device according to claim 1; anda damping element for oscillating coupling of the mounting member to thesteering wheel structure, wherein the damping element is arranged on theaxial bottom side of the mounting member and is preassembled togetherwith the mounting member on the steering wheel structure.
 11. Asubassembly comprising: a prefabricated airbag module; and a couplingdevice according to claim 1, wherein the prefabricated airbag moduleincludes a module cover including a horn contact as well as anothermodule component including a mating contact axially abutting on the horncontact, with the module cover being supported to be axially movablerelative to the further module component for activating a beep.
 12. Asubassembly comprising: a prefabricated airbag module; and a couplingdevice according to claim 4, wherein the prefabricated airbag moduleincludes a mating contact axially abutting on the horn contact, with theairbag module being supported to be axially movable relative to themounting member for activating a beep.
 13. A vehicle steering wheel ofan automotive vehicle, comprising a steering wheel structure; aprefabricated airbag module; a coupling device according to claim 1; anda damping element for oscillating coupling of the mounting member to thesteering wheel structure, wherein the vehicle steering wheel includes ahorn contact as well as a mating contact axially abutting on the horncontact, and wherein both the horn contact and the mating contact areformed on components of the vehicle steering wheel that are supported soas to be oscillating.
 14. The vehicle steering wheel according to claim13, wherein the airbag module is secured to the steering wheel structureexclusively by the locking connection to the coupling device.
 15. Thevehicle steering wheel according to claim 13, wherein the airbag moduleis secured to the steering wheel structure by means of the couplingdevice, wherein moreover another connection independent of the couplingdevice is provided between the airbag module and the steering wheelstructure.